He is a stage, film and television actor best known for Der Fahnder (1984), Die Straßen von Berlin (1995), and The Wonderful Years (1979).
From 1975 to 1979 he was at the Schauspielhaus Hamburg where, directed by Peter Zadek, he played the role of Rodrigo in Othello (1976), Camillo in The Winter's Tale (1978), Brinan in the German premiere of Ayckbourn's Jokes Aside (1979), and Kenneth in John Hopkins's Lost Time (1984).
In 1980-81 he was a guest at the Bavarian State Theatre in Munich, playing a doctor in August Strindberg's The Father, and in 1996-97 as President von Walter in Friedrich Schiller's Intrigue and Love.
In the 1984 TV film The Wannsee Conference (Ger., Die Wannseekonferenz), Mattausch was in the starring role of SS-Obergruppenführer Reinhard Heydrich, Chief of the Reich Security Main Office (RSHA) and Deputy Reichsprotektor of Bohemia and Moravia.
The film portrayed the events of the Wannsee Conference, held in Berlin in January 1942 to plan "The Final Solution" to Germany's "Jewish problem".